In conservation biology, which measure best captures ecosystem biodiversity by incorporating both species richness and species evenness?

• A. Net primary productivity (NPP), which increases as photosynthetic carbon fixation increases
• B. Total biomass per unit area, which increases as the combined mass of all organisms increases
• C. Population density of the most abundant species, which increases as that species becomes more common
• D. The Shannon diversity index, which increases with both the number of species and how evenly individuals are distributed among them

Answer: (D)

Verified step by step guidance

1. Understand the two key components of biodiversity: species richness (the number of different species in an ecosystem) and species evenness (how evenly individuals are distributed among those species).
2. Recognize that some measures focus only on one aspect, such as species richness alone or the abundance of a single species, which do not fully capture overall biodiversity.
3. Learn that the Shannon diversity index is a mathematical formula that combines both species richness and species evenness into a single value, providing a more comprehensive measure of biodiversity.
4. Recall the formula for the Shannon diversity index: \(H = -\sum_{i=1}^S p_i \ln(p_i)\), where \(S\) is the total number of species and \(p_i\) is the proportion of individuals belonging to species \(i\).
5. Conclude that because the Shannon index increases with both the number of species and the evenness of their distribution, it best captures ecosystem biodiversity compared to the other options.